Medication delivery device with sensing system

ABSTRACT

Medication delivery devices are provided having a dose delivery sensing capability. A sensed element is attached to a dose setting member of the device. The sensed element includes surface features radially-spaced from one another. A rotational sensor is attached to an actuator of the device. The rotational sensor includes a movable element that is contactable against the surface features. The rotational sensor is configured to generate a signal in response to the movement of the movable element over the surface features during their rotation. A controller is operatively coupled to the rotational sensor, and in response to receiving the generated signal, the controller is configured to determine a number of the surface features passing the movable element of the rotational sensor during dose delivery. The number can be associated with an amount of dose delivered. Sensing can be provided in a module or integrated in device.

BACKGROUND

The present disclosure relates to an electronic dose detection systemfor a medication delivery device and/or a module adapted to removablyattach to a proximal end portion of a medication delivery device. Thedose delivery detection system is operable to detect data fordetermining the amount of a dose of medication delivered by themedication delivery device.

Patients suffering from various diseases must frequently injectthemselves with medication. To allow a person to conveniently andaccurately self-administer medicine, a variety of devices broadly knownas pen injectors or injection pens have been developed. Generally, thesepens are equipped with a cartridge including a piston and containing amulti-dose quantity of liquid medication. A drive member is movableforward to advance the piston in the cartridge to dispense the containedmedication from an outlet at the distal cartridge end, typically througha needle. In disposable or prefilled pens, after a pen has been utilizedto exhaust the supply of medication within the cartridge, a userdiscards the entire pen and begins using a new replacement pen. Inreusable pens, after a pen has been utilized to exhaust the supply ofmedication within the cartridge, the pen is disassembled to allowreplacement of the spent cartridge with a fresh cartridge, and then thepen is reassembled for its subsequent use.

Many pen injectors and other medication delivery devices utilizemechanical systems in which members rotate and/or translate relative toone another in a manner proportional to the dose delivered by operationof the device. Systems to measure the relative movement of members of amedication delivery device have been developed in order to assess thedose delivered. Yet, systems integrated into the device or module forhigh volume manufacturing and repeatable accuracy during the product'slifecycle have been challenging to design. The administration of aproper amount of medication requires that the dose delivered by themedication delivery device be accurate. Many pen injectors and othermedication delivery devices do not include the functionality toautomatically detect and record the amount of medication delivered bythe device during the injection event. In the absence of an automatedsystem, a patient must manually keep track of the amount and time ofeach injection. Accordingly, there is a need for a device that isoperable to automatically detect the dose delivered by the medicationdelivery device during an injection event, and/or overcome one or moreof these and other shortcomings of the prior art.

SUMMARY OF THE DISCLOSURE

In one embodiment, a medication delivery device is provided, including adevice body, a dose setting member attached to the device body androtatable relative to the device body about an axis of rotation duringdose delivery. The dose setting member includes a sensed elementincluding surface features radially-spaced from one another about theaxis of rotation of the dose setting member. An actuator or a dosebutton is attached to the device body. The sensed element is rotatablerelative to the dose button during dose delivery in relation to theamount of dose delivered. A rotational sensor includes a movable elementcontactable against the surface features of the sensed element. The dosebutton may be configured to house the rotational sensor. The movableelement is positioned to move over the surface features during rotationof the sensed element relative to the dose button during dose delivery.The rotational sensor is configured to generate a signal in response tothe movement of the movable element over the surface features during therotation of the dose setting member. A controller is operatively coupledto the rotational sensor and may be housed by the dose button or amodule. In response to receiving the generated signal from therotational sensor, the controller is configured to determine a number ofthe surface features passing the movable element of the rotationalsensor during dose delivery.

In another embodiment of a medication delivery device, an actuator has afirst position in which a movable element of a rotational sensor isdisengaged from axially extending surface features, and a secondposition in which the movable element of the rotational sensor iscontactable with the axially extending surface features. The actuatormay be a dose button. When the actuator is in the second position, acontroller is configured, upon receiving a signal indicative of contactwith an initial first one of the axially extending surface features, toactivate the controller to a full power state, and the controller isconfigured, upon receiving a signal indicative of contact with asubsequent one of the axially extending surface features after theinitial first one, to determine a number of the axially extendingsurface features passing the movable element of the rotational sensorduring dose delivery.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional embodiments of the disclosure, as well as features andadvantages thereof, will become more apparent by reference to thedescription herein taken in conjunction with the accompanying drawings.The components in the figures are not necessarily to scale. Moreover, inthe figures, like-referenced numerals designate corresponding partsthroughout the different views.

FIG. 1 is a perspective view of an exemplary medication delivery devicewith which the dose detection system of the present disclosure isoperable.

FIG. 2 is a cross-sectional perspective view of the exemplary medicationdelivery device of FIG. 1 .

FIG. 3 is a perspective view of the proximal portion of the exemplarymedication delivery device of FIG. 1 .

FIG. 4 is a partially-exploded, perspective view of the proximal portionof the exemplary medication delivery device of FIG. 1 , and showing adose detection module.

FIG. 5 is a side, diagrammatic view, partially in cross section, of anexemplary embodiment of a dose detection system shown attached to theproximal portion of a medication delivery device.

FIG. 6 is a perspective view of a flange including a sensed element.

FIG. 7 is a perspective view of an embodiment of a sensed element.

FIG. 8 is a diagrammatic view of other exemplary embodiments of the dosedetection system.

FIG. 9 is a diagrammatic view showing an alternate form of biasingmember for the dose detection system.

FIG. 10 is a side, diagrammatic view, partially in cross section, of aproximal portion of another embodiment of a medication delivery devicewith a dose detection system, with a dose button in a proximal position.

FIG. 11 is a side, diagrammatic view, partially in cross section, of theproximal portion of the medication delivery device in FIG. 10 , with thedose button in a distal position.

FIG. 12 is a side magnified view of an example of a rotational sensorprovided in the medication delivery device in FIG. 10 , with the dosebutton in the proximal position.

FIG. 13 is a side magnified view of the rotational sensor in FIG. 12 ,with the dose button in the distal position.

FIG. 14 is an axial top view of a dose setting member, depicting anexample of surface features.

FIG. 15 is a side, diagrammatic view, partially in cross section, of aproximal portion of another embodiment of a medication delivery devicewith a dose detection system, with its dose button in a proximalposition.

FIG. 16 is a side, diagrammatic view, partially in cross section, of theproximal portion of the medication delivery device in FIG. 15 , with thedose button in a distal position.

FIG. 17 is a perspective view of an example of a flange with anotherexample of surface features along an axial surface.

FIG. 18 is a perspective view of a proximal portion of anotherembodiment of a medication delivery device with a dose detection system.

FIG. 19 is a side, diagrammatic view, partially in cross section, of theproximal portion of the medication delivery device in FIG. 18 , with itsdose button in a proximal position.

FIG. 20 is a perspective view of the proximal portion of the medicationdelivery device of FIG. 18 , depicting the arrangement of a rotationalsensor and the surface features.

FIG. 21 is an axial top view of the proximal portion of the medicationdelivery device of FIG. 18 , depicting the arrangement of a rotationalsensor and the surface features.

FIG. 22 is a side, diagrammatic view, partially in cross section, of aproximal portion of another embodiment of a medication delivery devicewith a dose detection system, with its dose button in a proximalposition.

FIG. 23 is a perspective view of another example of a flange withanother example of surface features along an inner radial surface.

FIG. 24 is an axial top view of the proximal portion of the medicationdelivery device of FIG. 22 , depicting the arrangement of the surfacefeatures.

FIG. 25 is a perspective view of another example of a rotational sensor,shown as a piezoelectric sensor.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the invention is thereby intended.

The present disclosure relates to sensing systems for medicationdelivery devices. In one aspect, the sensing system is for sensing ofrelative rotational movement between a dose setting member and anactuator of the medication delivery device in order to determine theamount of a dose delivered by a medication delivery device. The sensedrelative rotational movements are correlated to the amount of the dosedelivered. By way of illustration, the medication delivery device isdescribed in the form of a pen injector. However, the medicationdelivery device may be any device which is used to set and to deliver adose of a medication, such as pen injectors, infusion pumps andsyringes. The medication may be any of a type that may be delivered bysuch a medication delivery device.

Devices described herein, such as a device 10, 210, 410, 610 or 810, mayfurther comprise a medication, such as for example, within a reservoiror cartridge 20. In another embodiment, a system may comprise one ormore devices including device 10 and a medication. The term “medication”refers to one or more therapeutic agents including but not limited toinsulins, insulin analogs such as insulin lispro or insulin glargine,insulin derivatives, GLP-1 receptor agonists such as dulaglutide orliraglutide, glucagon, glucagon analogs, glucagon derivatives, gastricinhibitory polypeptide (GIP), GIP analogs, GIP derivatives,oxyntomodulin analogs, oxyntomodulin derivatives, therapeutic antibodiesand any therapeutic agent that is capable of delivery by the abovedevice. The medication as used in the device may be formulated with oneor more excipients. The device is operated in a manner generally asdescribed above by a patient, caregiver or healthcare professional todeliver medication to a person.

An exemplary medication delivery device 10 is illustrated in FIGS. 1-4as a pen injector configured to inject a medication into a patientthrough a needle. Device 10 includes a body 11 comprising an elongated,pen-shaped housing 12 including a distal portion 14 and a proximalportion 16. Distal portion 14 is received within a pen cap 18. Referringto FIG. 2 , distal portion 14 contains a reservoir or cartridge 20configured to hold the medicinal fluid to be dispensed through itsdistal outlet end during a dispensing operation. The outlet end ofdistal portion 14 is equipped with a removable needle assembly 22including an injection needle 24 enclosed by a removable cover 25. Apiston 26 is positioned in reservoir 20. An injecting mechanismpositioned in proximal portion 16 is operative to advance piston 26toward the outlet of reservoir 20 during the dose dispensing operationto force the contained medicine through the needled end. The injectingmechanism includes a drive member 28, illustratively in the form of ascrew, axially moveable relative to housing 12 to advance piston 26through reservoir 20.

A dose setting member 30 is coupled to housing 12 for setting a doseamount to be dispensed by device 10. In the illustrated embodiment, dosesetting member 30 is in the form of a screw element operative to spiral(i.e., simultaneously move axially and rotationally) about alongitudinal axis AA of rotation relative to housing 12 during dosesetting and dose dispensing. FIGS. 1-2 illustrate the dose settingmember 30 fully screwed into housing 12 at its home or zero doseposition. Dose setting member 30 is operative to screw out in a proximaldirection from housing 12 until it reaches a fully extended positioncorresponding to a maximum dose deliverable by device 10 in a singleinjection. The extended positon may be any position between a positioncorresponding to an incremental extended position (such as a dosesetting a 0.5 or 1 unit) to a fully extended position corresponding to amaximum dose deliverable by device 10 in a single injection and to screwinto housing 12 in a distal direction until it reaches the home or zeroposition corresponding to a minimum dose deliverable by device 10 in asingle injection.

Referring to FIGS. 2-4 , dose setting member 30 includes a cylindricaldose dial member 32 having a helically threaded outer surface thatengages a corresponding threaded inner surface of housing 12 to allowdose setting member 30 to spiral relative to housing 12. Dose dialmember 32 further includes a helically threaded inner surface thatengages a threaded outer surface of sleeve 34 (FIG. 2 ) of device 10.The outer surface of dial member 32 includes dose indicator markings,such as numbers that are visible through a dosage window 36 to indicateto the user the set dose amount. Dose setting member 30 further includesa tubular flange 38 that is coupled in the open proximal end of dialmember 32 and is axially and rotationally locked to dose dial member 32by detents 40 received within openings 41 in dial member 32. In oneexample, dose setting member 30 further includes an optional collar orskirt 42 positioned around the outer periphery of dial member 32 at itsproximal end. Skirt 42 is axially and rotationally locked to dial member32 by tabs 44 received in slots 46.

Dose setting member 30 therefore may be considered to comprise any orall of dose dial member 32, flange 38, and skirt 42, as they are allrotationally and axially fixed together. Dose dial member 32 is directlyinvolved in setting the dose and driving delivery of the medication.Flange 38 is attached to dial member 32 and, as described later,cooperates with a clutch to selectively couple dial member 32 with adose button. As shown, skirt 42 provides a surface external of body 11to enable a user to rotate dose dial member 32 for setting a dose.

In the embodiment illustrated in FIG. 18 , the dose button of theillustrated device 10 is one-piece component which combines both skirt42 and the dose button 56 of FIG. 1-4 . In this embodiment, the flangeis attached to the dial member and cooperates with a clutch, describedbelow, to selectively couple the dial member with the one-piece dosebutton, shown as button 656. The radial exterior surface of one-piecedose button 656 provides a surface external of the device body 11 torotate the dial member.

Skirt 42 illustratively includes a plurality of surface contours 48 andan annular ridge 49 formed on the outer surface of skirt 42. Surfacecontours 48 are illustratively longitudinally extending ribs and groovesthat are circumferentially spaced around the outer surface of skirt 42and facilitate a user's grasping and rotating the skirt. In analternative embodiment, skirt 42 is removed or is integral with dialmember 32, and a user may grasp and rotate dose dial member 32 for dosesetting.

Delivery device 10 includes an actuator 50 having a clutch 52 which isreceived within dose dial member 32. Clutch 52 includes an axiallyextending stem 54 at its proximal end. Actuator 50 further includes dosebutton 56 positioned proximally of skirt 42 of dose setting member 30,as shown. Dose button 56 includes a mounting collar 58 (FIG. 2 )centrally located on the distal surface of dose button 56. Collar 58 isattached to stem 54 of clutch 52, such as with an interference fit or anultrasonic weld, so as to axially and rotatably fix together dose button56 and clutch 52.

Dose button 56 includes a disk-shaped proximal end surface or face 60and an annular wall portion 62 extending distally and spaced radiallyinwardly of the outer peripheral edge of face 60 to form an annular lipthere between. Face 60 of dose button 56 serves as a push surfaceagainst which a force can be applied manually, i.e., directly by theuser to push actuator 50 in a distal direction. Dose button 56illustratively includes a recessed portion 66 centrally located onproximal face 60, although proximal face 60 alternatively may be a flatsurface. A bias member 68, illustratively a spring, is disposed betweenthe distal surface 70 of button 56 and a proximal surface 72 of tubularflange 38 to urge actuator 50 and dose setting member 30 axially awayfrom each other. Dose button 56 is depressible by a user to initiate thedose dispensing operation. In an alternative embodiment, skirt 42 isomitted from the device, and the annular wall portion 62 of dose button56 extends distally to a location approximately to the distal extent ofthe skirt relative to the dial member as shown in the figures.

Delivery device 10 is operable in both a dose setting mode and a dosedispensing mode. In the dose setting mode of operation, dose settingmember 30 is dialed (rotated) relative to housing 12 to set a desireddose to be delivered by device 10. Dialing in the proximal directionserves to increase the set dose, and dialing in the distal directionserves to decrease the set dose. Dose setting member 30 is adjustable inrotational increments (e.g., clicks) corresponding to the minimumincremental increase or decrease of the set dose during the dose settingoperation. For example, one increment or “click” may equal one-half orone unit of medication. The set dose amount is visible to the user viathe dial indicator markings shown through dosage window 36. Actuator 50,including dose button 56 and clutch 52, move axially and rotationallywith dose setting member 30 during the dialing in the dose setting mode.

Dose dial member 32, flange 38 and skirt 42 (when employed) are allfixed rotationally to one another, and rotate and extend proximally ofthe medication delivery device 10 during dose setting, due to thethreaded connection of dose dial member 32 with housing 12. During thisdose setting motion, dose button 56 is rotationally fixed relative toskirt 42 by complementary splines 74 of flange 38 and clutch 52 (FIG. 2), which are urged together by bias member 68. In the course of dosesetting, skirt 42 and dose button 56 move relative to housing 12 in aspiral manner from a “start” position to an “end” position. Thisrotation relative to the housing is in proportion to the amount of doseset by operation of the medication delivery device 10.

Once the desired dose is set, device 10 is manipulated so the injectionneedle 24 properly penetrates, for example, a user's skin. The dosedispensing mode of operation is initiated in response to an axial distalforce applied to the proximal face 60 of dose button 56. The axial forceis applied by the user directly to dose button 56. This causes axialmovement of actuator 50 in the distal direction relative to housing 12.

The axial shifting motion of actuator 50 compresses biasing member 68and reduces or closes the gap between dose button 56 and tubular flange38. This relative axial movement separates the complementary splines 74on clutch 52 and flange 38, and thereby disengages actuator 50, e.g.,dose button 56, from being rotationally fixed to dose setting member 30.In particular, dose setting member 30 is rotationally uncoupled fromactuator 50 to allow backdriving rotation of dose setting member 30relative to actuator 50 and housing 12. Also, since dose setting member30 and actuator 50 are free to relatively rotate, actuator 50 is heldfrom rotating relative to device housing 12 by the user's engagement ofdose button 56 by pressing against it.

As actuator 50 is continued to be axially plunged without rotationrelative to housing 12, dial member 32 screws back into housing 12 as itspins relative to dose button 56. The dose markings that indicate theamount still remaining to be injected are visible through window 36. Asdose setting member 30 screws down distally, drive member 28 is advanceddistally to push piston 26 through reservoir 20 and expel medicationthrough needle 24 (FIG. 2 ).

During the dose dispensing operation, the amount of medicine expelledfrom the medication delivery device is proportional to the amount ofrotational movement of the dose setting member 30 relative to actuator50 as the dial member 32 screws back into housing 12. The injection iscompleted when the internal threading of dial member 32 has reached thedistal end of the corresponding outer threading of sleeve 34 (FIG. 2 ).Device 10 is then once again arranged in a ready state or zero doseposition as shown in FIGS. 2 and 3 .

The dose delivered may be derived based on the rotation of dose settingmember 30 relative to actuator 50 during dose delivery. This rotationmay be determined by detecting the incremental movements of the dosesetting member which are “counted” as the dose setting member is rotatedduring dose delivery.

Further details of the design and operation of an exemplary deliverydevice 10 may be found in U.S. Pat. No. 7,291,132, entitled MedicationDispensing Apparatus with Triple Screw Threads for Mechanical Advantage,the entire disclosure of which is hereby incorporated by referenceherein. Another example of the delivery device is an auto-injectordevice that may be found in U.S. Pat. No. 8,734,394, entitled “AutomaticInjection Device With Delay Mechanism Including Dual Functioning BiasingMember,” which is hereby incorporated by reference in its entirety,where such device being modified with one or more various sensor systemsdescribed herein to determine an amount of medication delivered from themedication delivery device based on the sensing of relative rotationwithin the medication delivery device. Another example of the deliverydevice is a reusable pen device that may be found in U.S. Pat. No.7,195,616, entitled “Medication Injector Apparatus with Drive Assemblythat Facilitates Reset,” which is hereby incorporated by reference inits entirety, where such device being modified with one or more varioussensor systems described herein to determine an amount of medicationdelivered from the medication delivery device based on the sensing ofrelative rotation within the medication delivery device.

The dose detection systems use a sensing component and a sensedcomponent attached to members of the medication delivery device. Theterm “attached” encompasses any manner of securing the position of acomponent to another component or to a member of the medication deliverydevice such that they are operable as described herein. For example, asensing component may be attached to a member of the medication deliverydevice by being directly positioned on, received within, integral with,or otherwise connected to, the member. Connections may include, forexample, connections formed by frictional engagement, splines, a snap orpress fit, sonic welding or adhesive.

The term “directly attached” is used to describe an attachment in whichtwo components, or a component and a member, are physically securedtogether with no intermediate member, other than attachment components.An attachment component may comprise a fastener, adapter or other partof a fastening system, such as a compressible membrane interposedbetween the two components to facilitate the attachment. A “directattachment” is distinguished from attachment where thecomponents/members are coupled by one or more intermediate functionalmembers, such as the way dose dial member 32 is coupled in FIG. 2 todose button 56 by clutch 52.

The term “fixed” is used to denote that an indicated movement either canor cannot occur. For example, a first member is “fixed rotationally”with a second member if the two members are required to move together inrotation. In one aspect, a member may be “fixed” relative to anothermember functionally, rather than structurally. For example, a member maybe pressed against another member such that the frictional engagementbetween the two members fixes them together rotationally, while the twomembers may not be fixed together absent the pressing of the firstmember.

Various sensor systems are contemplated herein. In general, the sensorsystems comprise a sensing component and a sensed component. The term“sensing component” refers to any component which is able to detect therelative position or movement of the sensed component. The sensingcomponent includes a sensing element, or “sensor”, along with associatedelectrical components to operate the sensing element. The “sensedcomponent” is any component for which the sensing component is able todetect the position and/or movement of the sensed component relative tothe sensing component. For the dose detection system, the sensedcomponent rotates relative to the sensing component, which is able todetect the rotational movement of the sensed component. The sensingcomponent may comprise one or more sensing elements, and the sensedcomponent may comprise one or more sensed elements. The sensor systemdetects the movement of the sensed component and provides outputsrepresentative of the movement of the sensed component.

Illustratively, the dose detection system includes an electronicsassembly suitable for operation of the sensor system as describedherein. A controller is operably connected to the sensor system toreceive outputs from the rotational sensor. The controller beginsreceiving generated signals from the rotational sensor indicative ofcounts from first to last one for a total number of counts that is usedfor determining total angular displacement. The controller may beconfigured to receive data indicative of the angular movement of thedose setting member that can be used to determine from the outputs theamount of dose delivered by operation of the medication delivery device.The controller may be configured to determine from the outputs theamount of dose delivered by operation of the medication delivery device.The controller may include conventional components such as a processor,power supply, memory, microcontrollers, etc. Alternatively, at leastsome components may be provided separately, such as by means of acomputer, smart phone or other device. Means are then provided tooperably connect the external controller components with the sensorsystem at appropriate times, such as by a wired or wireless connection.

An exemplary electronics assembly 76 is shown in FIG. 5 and can includea flexible printed circuit board (FPCB) having a plurality of electroniccomponents. The electronics assembly comprises a sensor system includingone or more sensors operatively communicating with a processor forreceiving signals from the sensor representative of the sensed rotation.Circuit board of electronics assembly 76 further includes amicrocontroller unit (MCU) as the controller comprising at least oneprocessing core and internal memory. The system includes a battery,illustratively a coin cell battery, for powering the components. Thecontroller of electronics assembly 76 includes control logic operativeto perform the operations described herein, including detecting theangular movement of the dose setting components during dose settingand/or dose delivery and/or detecting a dose delivered by medicationdelivery device 10 based on a detected rotation of the dose settingmember relative to the actuator. Many of the components of theelectronics assembly may be contained in a compartment 78 locatedproximal of the dose button 56.

The controller of electronics assembly 76 is operative to store thetotal angular movement used for determining dose delivery and/or thedetected dose delivery in local memory (e.g., internal flash memory oron-board EEPROM). The controller is further operative to wirelesslytransmit a signal representative of the total counts, total angularmovement, and/or detected dose to a paired remote electronic device,such as a user's smartphone. Transmission may, for example, be over aBluetooth low energy (BLE) or other suitable short or long rangewireless communication protocol. Illustratively, the BLE control logicand controller are integrated on the same circuit.

The dose detection system involves detecting relative rotationalmovement between two members. With the extent of rotation having a knownrelationship to the amount of a delivered dose, the sensor systemoperates to detect the amount of angular movement from the start of adose injection to the end of the dose injection. For example, a typicalrelationship for a pen injector is that an angular displacement of adose setting member of 18° is the equivalent of one unit of dose,although other angular relationships are also suitable, such as, forexample, 9, 10, 15, 20, 24 or 36 degrees may be used for a unit or 0.5unit. The sensor system is operable to determine the total angulardisplacement of a dose setting member during dose delivery. Thus, if theangular displacement is 90°, then 5 units of dose have been delivered.

The angular displacement is determined by counting increments of doseamounts as the injection proceeds. For example, a sensing system may usea repeating pattern of a sensed element, such that each repetition is anindication of a predetermined degree of angular rotation. Conveniently,the pattern may be established such that each repetition corresponds tothe minimum increment of dose that can be set with the medicationdelivery device.

The sensor system components may be permanently or removably attached tothe medication delivery device. In an illustrative embodiment, as leastsome of the dose detection system components are provided in the form ofa module that is removably attached to the medication delivery device.This has the advantage of making these sensor components available foruse on more than one pen injector.

The sensor system detects during dose delivery the relative rotation ofthe sensed component, and therefore of the dose setting member, fromwhich is determined the amount of a dose delivered by the medicationdelivery device. In an illustrative embodiment, a rotational sensor isattached, and rotationally fixed, to the actuator. The actuator does notrotate relative to the body of the medication delivery device duringdose delivery. In this embodiment, a sensed component is attached, androtationally fixed, to the dose setting member, which rotates relativeto the actuator and the device body during dose delivery. In some of theembodiments described herein, the sensed component includes a ringstructure having a plurality of proximally extending projectionscircumferentially disposed relative to one another. Projections areshaped and sized to deflect a movable element of the rotational sensor.Embodiments described herein may be provided for a module that isremovably attachable to the dose button of the delivery device orintegrated within the dose button of the delivery device, with anembodiment illustrated in FIG. 10-11 .

Referring to FIG. 5 , there is shown in diagrammatic form a dosedelivery detection system 80 including a module 82 useful in combinationwith a medication delivery device, such as device 10. Module 82 carriesa sensor system, shown generally at 84, including a rotational sensor 86and other associated components such as a processor, memory, battery,etc. Module 82 is provided as a separate component which may beremovably attached to the actuator.

Dose detection module 82 includes a body 88 attached to dose button 56.Body 88 illustratively includes a cylindrical side wall 90 and a topwall 92, spanning over and sealing side wall 90. By way of example, inFIG. 5 side wall 90 is diagrammatically shown having inwardly-extendingtabs 94 attaching module 82 to dose button 56. Module 82 is therebyattached to dose button 56 such that pressing on the module delivers aset dose.

Dose detection module 82 may alternatively be attached to dose button 56via any suitable fastening means, such as a snap or press fit, threadedinterface, etc., provided that in one aspect module 82 may be removedfrom a first medication delivery device and thereafter attached to asecond medication delivery device. The attachment may be at any locationon dose button 56, provided that dose button 56 is able to move anyrequired amount axially relative to dose setting member 30, as discussedherein.

During dose delivery, dose setting member 30 is free to rotate relativeto dose button 56 and module 82. In the illustrative embodiment, module82 is rotationally fixed with dose button 56 and does not rotate duringdose delivery. This may be provided structurally, such as with tabs 94of FIG. 5 , or by having mutually-facing splines or other surfacefeatures on the module body 88 and dose button 56 engage upon axialmovement of module 82 relative to dose button 56. In another embodiment,the distal pressing of the module provides a sufficient frictionalengagement between module 82 and dose button 56 as to functionally causethe module 82 and dose button 56 to remain rotationally fixed togetherduring dose delivery.

Top wall 92 is spaced apart from face 60 of dose button 56 and therebyprovides a compartment 78 containing some or all of electronics assembly76. Compartment 78 defines a chamber 96 and may be open at the bottom,or may be enclosed, such as by a bottom wall 98. Bottom wall 98 may bepositioned to bear directly against face 60 of dose button 56.Alternatively, bottom wall 98 if present may be spaced apart from dosebutton 56 and other contacts between module 82 and dose button 56 may beused such that an axial force applied to module 82 is transferred todose button 56.

Further disclosed herein is a dose detection system operable todetermine the amount of dose delivered based on relative rotationbetween a dose setting member and the device body. The dose detectionsystem utilizes a dose setting member attached to the device body androtatable relative to the device body about an axis of rotation duringdose delivery. A sensed element is attached to and rotationally fixedwith the dose setting member. An actuator is attached to the device bodyand is held against rotation relative to the device body during dosedelivery. The sensed element thereby rotates relative to the actuatorduring dose delivery in relation to the amount of dose delivered.

The dose detection system comprises a sensor system including arotational sensor attached to the actuator. The sensed element includessurface features radially-spaced about the axis of rotation of the dosesetting member. The surface features may be arranged to correlate to theequivalent of one unit of dose, although other angular relationships arealso suitable, such as, for example, 9, 10, 15, 18, 20, 24 or 36 degreesmay be used for a unit or 0.5 unit. The rotational sensor includes amovable element attached to the actuator and having a contact portioncapable of resting against and spring-biased in the direction of thesurface features of the sensed element. The contact surface is therebypositioned to move over the surface features during rotation of thesensed element relative to the actuator during dose delivery. Therotational sensor is responsive to the movement of the contact portionover the surface features and generates signals corresponding to therotation of the dose setting member. A controller is responsive to thesignals generated by the rotational sensor to determine a dose count fordetermining the amount of dose delivery based on the detected rotationof the dose setting member relative to the actuator during dosedelivery.

The surface features may comprise anything detectable by the rotationalsensor. As previously indicated, sensor systems may be based on avariety of sensed characteristics, including tactile, optical,electrical and magnetic properties, for example. In one aspect, thesurface features are physical features which allow for detection ofincremental movements as the dose setting member rotates relative to theactuator.

The contact surface is biased against the physical features to ensureproper contact between the contact surface and the physical featuresduring rotation. In one embodiment, the movable element is a resilientmember having one portion attached to the actuator at a locationdisplaced from the contact surface. In one example, the movable elementis a following member comprising a beam attached at one end to theactuator and having the contact surface at the other end. The beam isflexed to urge the contact surface in the direction of the surfacefeatures. Alternatively, the movable element may be biased in any of avariety of other ways. In addition to the use of a resilient beam, thebiasing may be provided, for example, by use of a spring component. Suchspring component may for example comprise a compression, tension, ortorsion coil spring. In yet other embodiments, the movable element maybe biased against the surface features of the sensed element by aseparate resilient member or spring component bearing against themovable element.

In one embodiment, the surface features are uniform elements which arespaced intermittently around the axis of rotation of the sensed element.In a particular aspect, the surface features are equi-radially spacedprojections separated by intervening recesses. The contact surface ofthe movable element is positioned to ride over the projections, and tomove inwardly relative to the intervening recesses. The movable elementmay, for example, be a resilient beam which flexes outwardly along theprojections, or a translating member which rides up over theprojections.

In one aspect, the projections are ramped upward in the directionopposite to rotation of the sensed element during dose delivery tofacilitate movement of the contact surface along and over theprojections. In another aspect, the projections are provided withdiffering profiles in opposed angular directions to provide fordetecting the direction of rotation of the sensed element relative tothe actuator. The projections may extend in any direction detectable bythe movable element. For example, the projections may extend axially orradially. Axial projections may extend proximally or distally. Radialprojections may extend inwardly or outwardly.

The sensed element is attached to the dose setting member. Depending onthe medication delivery device, the sensed element may be attached tothe skirt, the flange or the dose dial, or any other component thatrotates relative to the device body during dose delivery in relation tothe amount of dose delivered.

In one aspect, the sensing system of dose detection system 80 isoriginally incorporated into a medication delivery device as anintegrated system. In another aspect, there is disclosed a modular formof the dose detection system. The use of a removably attached module isparticularly adapted to use with a medication delivery device in whichthe actuator and/or the dose setting member include portions external tothe medication device housing. These external portions allow for directattachment of the module to the actuator, such as a dose button, and/orattachment of a sensed element to a dose setting member, such as askirt, flange, or dose dial member, as described herein. Alternately,the sensed element is integral with the medication delivery device andthe module is removably attached. This has the advantage that the morecomplex and expensive electronics, including the rotational sensor andcontroller, may be reused with different medication deliver devices. Bycomparison, the sensed element may use relatively simple features, forexample radially-spaced projections, which do not add significantly tothe cost of the medication delivery device.

An exemplary medication delivery device incorporating an exemplary dosedetection system is shown in FIGS. 5-9 . The device includes a sensorsystem which detects surface features of a sensed element extending fromone or more of the components of dose setting device 30, such as thedose dial member 32 and/or flange 38. In particular, sensor system 84 ofdose detection system 80 includes the rotational sensor 86 and a sensedelement 99 having surface features. Examples of the location andarrangement of the surface features are shown in illustrative examples:axial surface features of the flange (for example, FIG. 6 ), axialsurface features of the dose dial member (for example, FIG. 10 ), outerradial surface features of the dose dial member (for example, FIG. 20 ),and inner radial surface feature of the flange (for example, FIG. 23 ).

In one example, shown in FIG. 6 , sensed element 99 includes a ring 100coupled to flange 38. It will be appreciated that ring 100 may bepermanently affixed to flange 38 (shown) or dose dial member 32 with anadhesives and/or fasteners, or it may be configured to be removablyattached to flange 38 or dose dial member, such as, for example, with amechanical fastener or a carrier component. The ring may be omitted andthe surface features may be integrally formed from flange 38 or doesdial member 32 as a unitary member (shown for example in FIG. 17 or 23), such as, for example, through molding or additive manufacturing.

As shown in FIGS. 6 and 7 , surface features 101 comprising a series oframp-like projections 102. Rotational sensor 86 includes one or moremovable elements 103 (FIG. 5 ), in this instance comprising a followingmember pin 104 which is received through a button aperture 105 definedby the face 60 of dose button 56 and is positioned to have a distalcontact surface 111 that is capable of resting against surface featuresshown as projections 102 as flange 38 rotates relative to dose button56. Pin 104 is shown extending through a module aperture 107 defined bythe distal bottom wall 98 that is in a coaxial alignment with buttonaperture 105. The interior surfaces that define the respective moduleaperture and button aperture may be configured to provide bearingsupport to the pin along two locations during its axial movement. Suchsize and arrangement of the apertures 105, 107 may enhance linear axialmotion of the pin to reduce inconsistent readings from the sensor orswitch employed. More than one pin and corresponding apertures definedby their respective component may be utilized for redundant sensing toreduce error readings.

Pin 104 may include a pin flange 106 received between contact surface111 and dose button 56. Coil spring 108 is positioned between pin flange106 and dose button 56 and biases pin 104 in the distal direction ofprojections 102. As flange 38 rotates during dose delivery, the pin(s)and dose button maintain their relative position, and contact surface111 of pin 104 rides up over each surface feature shown as projection102 against the biasing force of coil spring 108. Pin 104 then dropsdown into each recess 110 between adjacent projections. Pin 104 therebyoperates as a following member which follows the contours of theprojections and recesses.

Rotational sensor 86 further includes a sensing element 114 positionedto detect movement of pin 104 as it rides over projections 102 and fallsinto intervening recesses 110. The sensing element 114 may be providedin various forms operable to detect translational movement of pin 104.By way of example, the sensing element 114 is shown in FIG. 5 ascomprising a microswitch that is operated to detect axial movement ofpin 104 in the proximal direction each time pin 104 rides over aprojection 102. This activation will result in successive on-off oroff-on setting changes for the microswitch for each passage of aprojection/recess pair of ring 100.

In the manner previously described, rotational sensor 86 detects angularmovement of the dose setting member by counting the number ofprojections that trigger sensing element 114 during dose delivery.Rotational sensor 86 generates signals indicating this angular movementand those signals are used by the controller to determine the totalrotation of the dose setting member during dose delivery that can beused to determine the amount of the dose delivery. In one example, therotational sensor 86 generates signals indicative of a count number andthe controller receives the generated signal. Controller may store thenumber of counts to an internal memory and/or transmit electronicallythe number of counts to an external device. Controller may compare thenumber of counts to an internal database that correlates the number ofcounts to a total angular movement and thus a dose delivered. Thedetermined angular movement and/or dose delivered may be displayed on alocal display or indicator system (such as numbers) as part of theelectronics assembly and/or transmitted electronically to an externaldevice.

FIG. 8 shows alternative dose detection systems which similarly useradially-spaced projections 102 and movable members 103 which comprisepins 104 which ride along the successive projections and recesses. Asshown in FIG. 8 , each movable member 103 includes a contact surface 116which moves over the surface features 101 radially-spaced about the axisof rotation, e.g., projections 102. The contact surface 116 of pin 104is shown in FIG. 8 as including an enlarged end portion 118 which maydesirably be made of a durable, low-friction material which allows pin104 to slide easily across projections 102. The enlarged end portion 118having a cross-sectional area larger than the cross-sectional area ofthe pin. Also as shown in FIG. 8 , projections 102 may be formed with asurface 120 which is ramped upward in the direction opposite to thedirection of rotation, shown by arrow 122, of the dose setting member.This further facilitates movement of the following member over theprojections.

In another aspect, the opposite side of projections 102 may be ramped toallow for rotation of the dose setting member in the opposite direction.Further, the two sides of the projections may be provided with differentangles of inclination to allow the dose detection system to detect thedirection of rotation. On the other hand, the opposite sides of theprojections may be angled more steeply to prevent rotation in the otherdirection.

Described herein is an embodiment in which the actuator is moveddistally relative to the device body to transition from a dose settingmode, or an at rest position, to a dose delivery mode. In the proximallydisplaced condition, the following members may be separated from theprojections as one way to allow for rotation of the sensed elementrelative to the actuator in the direction opposite from dose delivery.However, as also described, in certain embodiments the actuator isrotationally fixed to the dose setting member during dose setting.

In FIG. 8 there is shown an alternative dose detection system whichoperates by detecting vibrations associated with rotation of the sensedelement relative to the actuator during dose delivery. As sensed element99 rotates in direction 122 relative to movable member 103, contactsurface 116 forces pin 104 away from the dose setting member and againstthe biasing member, e.g., spring 108. Once the contact surface 116passes over the top of the projection, the biasing member forces thefollowing member quickly down into the subsequent recess 110. Referringto FIG. 8 , with additional movement of sensed element 99 in thedirection 122, spring 108 will drive pin 104 down into recess 124, whereit will be stopped abruptly by contact with the bottom of the followingrecess 124. This abrupt stop will be accompanied by a vibration which isdetected by the rotational sensor.

For example, in FIG. 8 there is shown a support 126 attached to theproximal end of pin 104 and carrying a rotation accelerometer 128.Rotation accelerometer 128 is provided primarily to detect vibrationsindicative of rotation of the sensed element. In operation of thesystem, accelerometer 128 detects each vibration associated with thepassage of pin 104 over the top of a projection and falling into thefollowing recess. Accelerometer 128 may be of any type capable ofdetecting the vibration, and in a particular aspect comprises a 3-axesaccelerometer. As used herein, this accelerometer is referred to as a“rotation accelerometer” to distinguish it as an accelerometer used indetecting rotation of the sensed element, rather than to suggest aparticular type of accelerometer. Other sensors capable of detecting therotation vibrations may also be used.

Also shown in FIG. 8 are optional sensor components including a secondsupport 130 and a second accelerometer 132 that are useful inconjunction with rotation accelerometer 128. As used herein, the secondaccelerometer is referred to as a “background accelerometer” todistinguish it as an accelerometer used in detecting backgroundvibrations, rather than to suggest a particular type of accelerometer.Background accelerometer 132 is provided primarily to detect backgroundvibrations, such as caused by movement of the entire medication deliverydevice, which vibrations are not indicative of rotation of the sensedelement. For this purpose, background accelerometer 132 is relativelyisolated from pin 104, such as by pin 104 being slidingly receivedwithin an aperture in dose button 56.

Significant axial movement of pin 104 relative to dose button 56 will besensed more strongly by rotation accelerometer 128 than by backgroundaccelerometer 132. If a vibration sensed by the rotation accelerometeris substantially the same as that sensed by the backgroundaccelerometer, then rotation of the sensed element will not beindicated. By comparison, if the amount of vibration detected by therotation accelerometer is substantially greater than that detected bythe background accelerometer at a given time, then rotation of thesensed element is indicated. The controller compares detected rotationvibrations and background vibrations to identify vibrations indicativeof rotation of the sensed element relative to the actuator during dosedelivery.

The action of the following member during rotation of the sensed elementmay also be associated with related sounds. In particular, a distinctivesound will be made by the impact of pin 104 against the bottom of recess124. An alternative dose detection system utilizes this sound to detectrotation of sensed element 99 relative to dose button 56. By way ofexample, also shown in FIG. 8 is a microphone 134 forming a component ofan alternative sensing system. Upon detecting a sound predetermined tobe an indicator of rotation of the sensed element, the rotational sensorgenerates a signal identifying rotation of the sensed element associatedwith dose delivery. An additional background sound microphone may beused in order to be able to distinguish rotation sounds from othersounds.

As shown in FIG. 8 , the following member may be biased, for example, bya coil spring. Alternatively, the following member may be biased againstthe surface features in various other ways. For example, a resilientmember may be used to bias pin 104 against projections 102. As shown inFIG. 9 , resilient member 136 is attached at one end to the underside138 of dose button 56. Resilient member 136 includes a portion 140 atthe opposite end resting against the enlarged end portion of the contactsurface 116 of pin 104. Movement of contact surface 116 over theprojections causes the pin to translate upwardly against the downward ofresilient member 136, and contact surface 116 is thereby maintained inposition against the surface features. Illustratively, in lieu of pin104, the following member may comprise resilient member 136 and thecontact surface may be positioned on end portion 140.

Referring now to FIGS. 1-2 , there is shown a medication delivery deviceequipped with a sensing system that is described further as being usedto determine the amount of a dose set by operation of the device. Suchamount is determined based on the sensing of relative rotationalmovements during dose setting between members of the medication deliverydevice, where the sensed movements are correlated as applicable to theamount of the dose set. In different embodiments, the sensing system isconfigured to determine the amount of at least one of the dose set andthe dose delivered by operation of the device, or alternatively both theamount of the dose set and the amount of the dose delivered by operationof the device.

FIGS. 10-11 illustrate the proximal portion of the device, nowreferenced as 210, with the dose detection sensor system 284 disposedwithin the dose button 256, rather than a module, and including therotational sensor 286. The device 210 includes many of the samecomponents operational for dose setting and dose dispensing as describedwith reference to the device 10, including at least a portion of theelectronic components in the electronics assembly, and such componentswill have the same corresponding descriptions. Although the device 210is shown as a device within an integrated dose detection sensing system,such sensing system may be incorporated in a module for removableattachment to a dose button.

The dose setting member 230 is coupled to the device housing 212 forsetting a dose amount to be dispensed by device 210. Dose setting member230 is operative to screw out in a proximal direction from housing 212until it reaches a fully extended position corresponding to a maximumdose deliverable by device 210 in a single injection. The cylindricaldose dial member 232 of dose setting member 230 includes the helicallythreaded outer surface that engages the corresponding threaded innersurface of housing 212 to allow dose setting member 230 to spiralrelative to housing 212. Dose dial member 232 includes the helicallythreaded inner surface that engages the threaded outer surface of thesleeve of the device 210, such as sleeve 34 in FIG. 2 . The outersurface of dial member 232 includes dose indicator markings that arevisible through the dosage window 236 to indicate to the user the setdose amount. Tubular flange 238 of dose setting member 230 is coupled inthe open proximal end of dial member 232 and is axially and rotationallylocked to dose dial member 232 by detents received within openings indial member 232, such as, for example, shown in FIG. 2 .

The actuator 250 of delivery device 210 includes the clutch 252 that isreceived within dose dial member 232. The proximal end of the clutch 252includes the stem 254 that is axially extending from its proximal end.Dose button 256 of actuator 250 is positioned proximally of dose settingmember 230, as shown. The mounting collar 258 of dose button 256 isattached to stem 254 of clutch 252, such as with an interference fit oran ultrasonic weld, so as to axially and rotatably fix together dosebutton 256 and clutch 252. The bias member 268, illustratively a spring,is disposed between the distal surface of mounting collar 258 of thedose button and the proximal surface of tubular flange 238 of the dosesetting member to urge actuator 250 and dose setting member 230 axiallyaway from each other. Dose button 256 is depressible by a user toinitiate the dose dispensing operation. Bias member 268 biases the dosebutton 256 in the proximal first position (as shown in FIG. 10 ) whereit stays during dose setting operation, until the user applies an axialforce great enough to overcome the biasing force of member 268 to movethe dose button 256 to the distal second position (as shown in FIG. 11 )for dose dispensing operation.

Dose button 256 includes an upper proximal wall 261 with the disk-shapedproximal end surface 260 and the annular wall portion 262 extendingdistally from the proximal wall 261 to define a button housing cavity265. Surface 260 of dose button 256 serves as the push surface againstwhich a force can be applied manually, i.e., directly by the user topush actuator 250 in a distal direction. Dose button 256 include adistal wall 263 axially spaced from the proximal wall 261. Distal wall263 may at least partially divide the cavity 265 into two proximal anddistal cavity portions. The mounting collar 258 of dose button 256 isshown extending distally from an intermediate location of the distalwall 263 for attachment with stem 254 of clutch 252. In one example, thesurface features 301 are disposed within the cavity 265 radially outsidebias member 268. As shown, the rotational sensor and the controller aredisposed within the cavity 265.

Distal wall 263 may be configured to allow a portion of the sensorsystem to extend distally beyond the distal wall 263. Distal wall 263may include a discrete opening or may extend partially across the cavity265 from a portion of the annular wall portion 262 to stop short of theopposite end of annular wall portion to define an axial aperture 269, asshown in FIGS. 10-11 . The axial aperture 269 may be spaced radiallyfrom the axis AA toward the outer end so that the rotational sensor thatextends through the aperture 269 is placed over the surface features 301that are radially-spaced about the axis AA of rotation. The electronicsassembly 276 is shown housed within the dose button 256. The circuitboard 325 includes a plurality of electronic components, and is shownmounted on the proximal face of the distal wall 263. The sensor system284 includes the rotational sensor 286 operatively communicating withthe processor of the controller of the circuit board for receivingsignals from the sensor representative of the sensed rotation. Therotational sensor 286 is shown mounted to a distal face of the circuitboard. The controller of the electronics assembly 276 includes at leastone processing core in electric communication with the rotational sensor286 and internal memory. The assembly 276 includes a battery B,illustratively a coin cell battery, for powering the electronicscomponents. The controller includes control logic operative to performthe operations described herein, including detecting a dose delivered bythe medication delivery device based on a detected rotation of the dosesetting member relative to the actuator. Some of the components in theelectronics assembly 276 are shown as unconnected for illustrativepurposes only, and are actually electrically connected to one another,such as by connectors, wires, or conduits, as understood in the art,such as shown by 297 in FIG. 10 , and illustrated in other figures.

Sensor system 284 with the rotational sensor 286 is configured to detectsurface features 301 extending from one or more of the components ofdose setting device 230, such as the dose dial member 232 (as shown)and/or flange 238. For example, with reference to FIG. 14 , the axialend surface 233 of the dose dial member 232 of the dose setting device230 in the shape of a ring may define surface features 301, shown asprojections 302 spaced radially from one another along the axial endsurface, projections separated by intervening recesses 310. In theexample shown, there are eighteen projections, each spaced twentydegrees apart from adjacent ones.

The dose button 256 is movable relative to device housing 212 betweentwo positions. In FIG. 10 , the dose button 256 is in the proximalposition where the device is in a first operating dose setting mode inwhich the dose button may be used to set a dose. In FIG. 11 , the dosebutton 256 is in the distal position where the device is in a secondoperating dose delivery mode in which the dose button may be used todeliver the dose. In certain embodiments, the dose button 256 isrotationally fixed to the dose setting member in the dose setting mode,and dose button 256 may be rotated to set a dose. In this position,rotational sensor 286 is axially displaced from the surface features301. In the dose setting mode, the rotational sensor 286 may remaininoperable and the electronics assembly may remain powered off or in alow power state.

Upon pressing proximal wall 261, dose button 256 advances distallyrelative to housing 212, compressing spring 268, as shown in FIG. 11 .Continued pressing of the dose button 256 distally results in backdriving dose dial 232 in a spiral direction relative to housing 212. Asa result, the dose dial 232 and flange 238 is driven to rotate by theaxially moving dose button. The dose detection system may only beoperable for counting when the dose button is being pressed. Theelectronics assembly may include a clock or timer to determine the timeelapsed between counts caused by trigger of the rotational sensor fromthe surface features of the sensed element. When trigger arm is notactivated, that is, no counts detected by the controller, for a periodof time, this may be used to indicate that the dose is completed.

Upon the sensing of the initial one of surface features 301, thecontroller is configured to allow wake-up or activation of theelectronics assembly 276 to a greater or full power state. Triggering ofwake-up feature is configured to allow power transmission from the powersource (shown as battery) for powering up the electronic components fordose sensing in order to minimize inadvertent power loss or usage when adose dispensing event is not occurring. In other embodiments, a separatewake-up switch may be provided and arranged within the dose buttonhousing and triggered when the dose button 256 is in its distalposition. In this instance, the wake-up switch may be located, forexample, along the upper end of the flange. After activation of theelectronics assembly, the controller begins receiving generated signalsfrom the rotational sensor indicative of counts from first to last onefor a total number of counts that is used for determining total angulardisplacement and thus the amount of dose delivered.

FIGS. 12-13 depict one example of the rotational sensor 286 provided inthe device 210. For example, the rotational sensor 286 includes a sensorbody 320 and a movable element comprising a pair of contacts 324, 326.The contacts 324, 326 may be resilient, that is having a naturalconfiguration in one state, and capable of being moved or deflected toanother state when under a force and returning to the naturalconfiguration when the force is removed. The sensor body 320 is shownmounted to the circuit board 325 and is operably coupled to thecontroller of electronics assembly, and is configured to transmit asensor signal of an electronic characteristic (voltage, resistance,current signal) defined by the contacting or separation of the contacts324, 326 to the controller. The contacts 324, 326 may remain spacedapart in a natural state until brought together in contact with oneanother in an operational state by deflection of at least one of thecontacts (shown as contact 326) during engagement with the surfacefeatures 301. Alternatively, both of contacts 324, 326 may be configuredto deflect upon engagement with surface features and contact one anotherdue to the deflection. After engagement of contact 326 with the surfacefeature 301, the contact 326 may return to the natural state where it isin spaced relationship with contact 324. Alternatively, the contacts324, 326 may remain contacting each other in a natural state andconfigured to separate from a contacting relationship due to engagementwith the surface features 301, and return to the natural state in theircontacting relationship after the passage of the surface feature.According to FIG. 12 , the rotational sensor 286 is in the proximalposition as the dose button 256 is in its proximal position where thedevice is in its first operating dose setting mode. According FIG. 13 ,the rotational sensor 286 is in the distal position as the dose button256 is in its distal position where the device is in its secondoperating dose delivery mode.

FIGS. 12-13 illustrate an example configuration of the contacts 324,326, although other configurations of the contacts may be utilized. Thefirst contact 324 is shown extending axially from the sensor body 320.The first contact 324 includes a first segment 330 coupled to the sensorbody 320 and a second segment 332 extending from the first segment 330.The first segment 330 is shown extending axially from the sensor body320, and the second segment 332 is shown extending radially from thefirst segment 330 at an elbow connection. The second contact 326includes a first segment 340 coupled to the sensor body 320 and a secondsegment 342 extending from the first segment 340. The first segment 340is shown extending axially from the sensor body 320. The second segment342 is shown extending generally radially from the first segment 340 atan elbow connection. The second segment 342 includes an arm portion 344,a transition engagement portion 346, and a tip contact portion 348coupled in sequence from the first segment 340. The arm portion 344 issized and shaped to place the tip contact portion 348 underneath thesecond segment 332 of the first contact. The arm portion 344 is shownextending at an incline in the axial and radial directions from thefirst segment 342. The transition engagement portion 346 is configuredto engage directly the surface feature 301. The transition engagementportion 346 may have a U-shape, V-shape, or ramped shape to transitionthe second segment 342 from the distal direction to the proximaldirection. The tip contact portion 348 extends in the radial directionand may be generally in parallel and spaced apart with respect to thesecond segment 332 of the first contact 324 in the natural state. Theshape of the transition engagement portion 346 may allow for slidingcontact along the surface features 301 without causing jamming of therotating dose dial member. The depth of the shape of the transitionengagement portion 346 is sized such that upon its distal surfaceengaging the surface features 301, the second contact 326 defects in theproximal direction at the elbow with the first segment to place theproximal surface of the tip contact portion 348 in contact with thedistal surface of the second segment 332 of the first contact 324. Suchcontact is sufficient to generate a sensor signal of an electroniccharacteristic. Alternatively, one of the contacts may be employed, suchas contact 326 and the surface features may have an electricalconductive property, such as being coated with a metallic material, suchthat upon engagement between the contact and the surface feature therotational sensor can generate a signal, as described herein.

FIGS. 15-16 depict the proximal portion of the device, now referenced as410. The device 410 includes many of the same components operational fordose setting and dose dispensing as described with reference to thedevice 10 or 210, including at least a portion of the electroniccomponents in the electronics assembly for the dose detection system,and such components will have the same corresponding descriptions.Although the device 410 is shown as a device within an integratedsensing system, such sensing system may be incorporated in a module forremovable attachment to a dose button. The device 410 may have the samedevice components as device 210, such as, for example, device housing412, dose dial member 432, flange 438, and electronics assembly 476,except with respect to a different rotational sensor configuration and adifferent dose setting member with the surface features used forsensing, as will be described. As shown, the rotational sensor and thecontroller are disposed within the cavity of the button.

Another example of the rotational sensor, referenced generally as 486,of the dose detection sensor system 484 that can be used with any moduleand/or device described herein. For example, the rotational sensor 486is a microswitch including a sensor body 490 and a movable elementcomprising a trigger arm 492. With reference to the previous figures,the dose button housing is configured to include the axial aperturespaced radially from the axis AA toward the outer end in order fortrigger arm 492 of the rotational sensor 486 to extend through forplacement over the surface features 501 that are radially-spaced aboutthe axis AA of rotation. The trigger arm 492 is biased by an internalspring into a natural state until being overcome by a force to urge thetrigger arm 492 into a position away from the natural state position toan operational state. The sensor body 490 is mounted to the circuitboard 525 and is operably coupled to the controller of electronicsassembly, and is configured to transmit a sensor signal of an electroniccharacteristic (voltage, resistance, current signal) defined by thetrigger arms movement to the controller. The trigger arm 492 may remainin the natural state until brought into engagement with the surfacefeatures 501. After engagement between trigger arm 492 with the surfacefeature 501, the trigger arm 492 may return to the natural state.According to FIG. 15 , the rotational sensor 486 is in the proximalposition as the dose button 456 can be biased in its proximal positionwhere the device 410 is in its first operating dose setting mode. Thebias member (not shown) may be axially disposed between the dose buttonand the dose setting member, and the surface features 501 are disposedradially outside the bias member, such as shown in FIGS. 10-11 .According FIG. 16 , the rotational sensor 486 is in the distal positionas the dose button 456 is in its distal position where the device is inits second operating dose delivery mode.

FIG. 17 shows one example of a dose setting member having the surfacefeatures 501. In one example, the axial surface 437 of the proximal endof the flange 438 may be integrally defined with the surface features,shown as projections 502 with intervening recesses 510, such as a moldedpart or part made with additive manufacturing. In another example, aring component with the surface features defined along one of itssurfaces may be coupled to the axial surface of the flange. It will beappreciated that ring may be permanently or temporarily affixed toflange with an adhesives and/or fasteners. In another example, thesurface features are formed or otherwise coupled to the dose dialmember.

As shown in FIGS. 15-17 , surface features 501 includes a series ofprojections 502 each having a ramp-like shape. Projections 502 may beformed with a surface which is ramped upward in the direction oppositeto the direction of rotation, shown by arrow 511, of the flange 438.This further facilitates movement of the trigger arm 492 over theprojections 502. In another aspect, the opposite side of projections 502may be ramped to allow for rotation of the dose setting member in theopposite direction. Further, the two sides of the projections 502 may beprovided with different angles of inclination to allow the dosedetection system to detect the direction of rotation. On the other hand,the opposite sides of the projections 502 may be angled more steeply toprevent rotation in the other direction.

The following embodiments illustrate different arrangements of therotational sensor and surface features along a radial direction. FIGS.18-21 illustrates the proximal portion of the device, now referenced as610, depicting the rotational sensor of the dose detection systempositioned radially outward relative to surface features that extendradially outward. The device 610 includes many of the same componentsoperational for dose setting and dose dispensing as described withreference to the device 10, 210, or 410, including at least a portion ofthe electronic components in the electronics assembly for the dosedetection system, and such components will have the same correspondingdescriptions. Although the device 610 is shown as a device within anintegrated sensing system, such sensing system may be incorporated in amodule for removable attachment to a dose button. Although therotational sensor is shown as a microswitch that is similar to what isshown in FIG. 15 , the rotational sensor can be any of sensors describedherein. The device 610 may have the same device components as device210, such as, for example, device housing 612, dose dial member 632,flange 638, and electronics assembly 676, except with respect to adifferent rotational sensor configuration and a different dose settingmember with the surface features used for sensing, as will be described.

The rotational sensor 686 of the sensor system 684 is shown disposedalong the annular wall portion 662 of the of the dose button 656. Thesensor body 690 of the rotational sensor 686 may be within an aperture695 defined by the annular wall portion 662 or, in alternativeembodiments, the sensor body 690 may be disposed along an interiorsurface of the wall portion 662. The movable element comprises thetrigger arm 692 that extends radially inward toward the longitudinalaxis AA. Although not shown, the rotational sensor 686 is operablycoupled to the controller of the electronics assembly, such as, viaelectrical conductors connected between the sensor 686 and the circuitboard that extend along the interior surface of the dose button housing.The rotational sensor 686 is configured to transmit a sensor signal ofan electronic characteristic (voltage, resistance, current signal)defined by movement of the trigger arm of the rotational sensor 686 tothe controller.

FIGS. 19-21 show the flange having the surface features. In one example,the outer radial surface 639 of a proximal annular end 641 of the flange638 may be integrally defined with the surface features 701 thatradially-spaced about the axis of rotation, shown as radial projections702 with intervening recesses 710, such as a molded part or part madewith additive manufacturing. In another example, a ring component withthe surface features 701 defined along the outer radial surfaces may becoupled to the axial surface of the flange. It will be appreciated thatring may be permanently or temporarily affixed to flange with anadhesives and/or fasteners. In another example, the surface features 701are formed or otherwise coupled to the dose dial member. Surfacefeatures may include a series of ramp-like projections as describedpreviously. The radial projections 702 may extend between a proximal endand a distal end to define axial ridges.

FIGS. 18-19 illustrate the rotational sensor in the proximal position asthe dose button 656 is in its proximal position where the device 610 isin its first operating dose setting mode. The dose button 656 is movableto its distal position (with reference to FIGS. 20-21 ) to place therotational sensor in the distal position where the device is in itssecond operating dose delivery mode. In one example, the trigger arm 692may enter through one of the recesses 710 from the proximal end when thedose button is being moved to its distal position so that the triggerarm is engageable with the surface features. Controller is capable ofcounting the number of times the trigger arm moves between a firsttrigger and last trigger and such data is used for determining a dosedelivery.

FIG. 22 illustrates the proximal portion of the device, now referencedas 810, depicting the rotational sensor positioned radially inwardrelative to surface features that extend radially inward. The device 810includes many of the same components operational for dose setting anddose dispensing as described with reference to the device 10, 210, 410or 610, including at least a portion of the electronic components in theelectronics assembly for the dose detection system 844, and suchcomponents will have the same corresponding descriptions. Although thedevice 810 is shown as a device within an integrated sensing system,such sensing system may be incorporated in a module for removableattachment to a dose button. The device 810 may have the same devicecomponents as device 210, such as, for example, device housing 812, dosedial member 832, flange 838, dose button 856, and electronics assembly876, except with respect to a different rotational sensor configurationand a different dose setting member with the surface features used forsensing, as will be described.

Like the arrangement of the rotational sensor 286, the rotational sensor886 is shown extending from the distal face of the circuit board throughthe axial aperture 869. The sensor body of the rotational sensor 886 ismounted to the circuit board and is operably coupled to the controllerof electronics assembly 876, and is configured to transmit a sensorsignal of an electronic characteristic (voltage, resistance, currentsignal) defined by movement of the movable element that is comprised ofthe trigger arm of the rotational sensor 886 to the controller. Themounting of the rotational sensor 886 is arranged to place its triggerarm within periphery of a proximal annular end 841 of the flange 838 andfacing radially outward for engagement with the surface features 901.

FIGS. 23-24 show the flange 838 having the surface features. In oneexample, the inner radial surface 839 of the proximal annular end 841 ofthe flange 838 may be integrally defined with the surface features 901that are radially-spaced about the axis of rotation, shown asprojections 902 with intervening recesses 910, such as a molded part orpart made with additive manufacturing. In another example, a ringcomponent with the surface features defined along the outer radialsurfaces may be coupled to the axial surface of the flange. It will beappreciated that ring may be permanently or temporarily affixed toflange with an adhesives and/or fasteners. In another example, thesurface features 901 are formed or otherwise coupled to the dose dialmember. Surface features 901 may include a series of ramp-likeprojections. The surface features may extend between a proximal end anda distal end to define an axial ridge.

FIG. 25 illustrates the rotational sensor as a piezoelectric sensor 1000that can be used with any of the devices 10, 210, 410, 610 or 810. Thepiezoelectric sensor 1000 may be oriented similarly to the rotationalsensors described above, such as axial, radially outward or radiallyinward. In one example, the trigger arm 1002 of the piezoelectric sensor1000 is defined as a film of piezoelectric material that is bendable.The film extends from the sensor body 1004, and the sensor body 1004includes a first electrode 1006 and a second electrode 1008. The sensorbody may include a polymer cast housing, such as, for example,fluoropolymer (e.g., polyvinylidene fluoride) or polyurethane.Piezoelectric sensor 1000 is a transducer that converts mechanicalenergy to electrical energy. More specifically, piezoelectric sensor1000 converts mechanical deformation of the trigger arm 1002 to aproportional electrical signal (charge or voltage). Thus, when thetrigger arm 1002 of piezoelectric sensor is subjected to a mechanicalforce and undergoes deformation or strain, piezoelectric sensor 1000 isconfigured to generate a proportional electrical signal between firstelectrode 1006 and second electrode 1008 for detection by an analogvoltage detector of the electronics assembly. The mechanical deformationof trigger arm 1002 of piezoelectric sensor 1000 may be resilient, suchthat trigger arm 1002 is able to return to its original, natural shapewhen the force is removed.

Controller of the electronics assembly may be configured to receive ananalog piezoelectric signal from the voltage detector of eachpiezoelectric sensor 1000, which may be a substantially ring-shapedsignal. Controller of the electronics assembly may be programmed toconvert the analog piezoelectric signal to a digital signal, such as,for example, an intermediate digital signal, which may be ahigh-frequency signal that represents the time of the “click” ordeformation event. Controller of the electronics assembly may be furtherprogrammed to convert the intermediate digital signal to a conditioneddigital signal, which may be a single step/square wave with apredetermined width W representing a predetermined time, as describedfurther below.

A signal processing logic for use by control system. Logic subject theanalog piezoelectric signal to a direct current (DC) voltage offset stepusing resistors, followed by an amplification step using amplifier, andfollowed by an analog-to-digital conversion step using comparator togenerate the intermediate digital signal. The signal may be generatedwhen the incoming voltage is at or above a predetermined voltage (e.g.,1.3 V). Alternatively, the signal may be ignored when the incomingvoltage is less than the predetermined voltage. The intermediate digitalsignal may be converted to the conditioned digital signal by turning thesignal “on” when initiating a timer at a timer initiation step andturning the signal “off” when the timer expires after a predeterminedtime at a timer expiration step. The timing steps may be performed usinga resistance-capacitance (RC) timing loop. The predetermined timeassociated with the timing steps may control the width W of theconditioned digital signal and may be adjusted to match the time of eachrotation and deformation event to minimize errors. Logic may output anumber corresponding to the number of digital signals counted over aperiod of time.

The devices described herein, such as, for example, devices 210, 410,610 or 810, may include the dose detection system involving detectingrelative rotational movement between two members. With the extent ofrotation having a known relationship to the amount of a delivered dose,the sensor system in any of the embodiments described herein operates todetect the amount of angular movement from the start of a dose injectionto the end of the dose injection. The angular displacement is determinedby counting increments of dose amounts as the injection proceeds. Forexample, a sensing system may use a repeating pattern of a sensedelement, such that each repetition is an indication of a predetermineddegree of angular rotation. Conveniently, the pattern may be establishedsuch that each repetition corresponds to the minimum increment of dosethat can be set with the medication delivery device. Controller isconfigured to count the number of generated signals. The count may betransmitted electronically to an external device. External devicedescribed herein may refer to a server, mobile phone, or other knowncomputer systems. The count may be correlated to an absolute rotationalangle, which is then used by a processor of the external device todetermine the amount of dose delivered. The signal generated by theinitial contact of the contacts may be operable to wake-up or activatethe controller, as previously described.

In the manner previously described, any of the rotational sensorsdescribed herein, such as rotational sensors 286, 486, 686, 886, detectsangular movement of the dose setting member by counting the number ofsurface features that trigger activation of trigger arm during dosedelivery. Each of rotational sensors generates signals indicating thisangular movement and those generated signals are used by the controllerof electronics assembly to determine the total number of counts orunits. Such total number of counts have a corresponding total rotationof the dose setting member during dose delivery, and thereby the amountof the dose delivery. In one example, each of the rotational sensorsgenerates signals indicative of a count number and the controllerreceives the generated signal. Controller may store the number of countson-board in internal memory and/or transmit the number of counts to anexternal device. Controller may compare the number of counts to anon-board database that correlates number of counts to a total angularmovement. The determined angular movement may be displayed on a localdisplay and/or transmitted to an external device.

The devices described herein, such as, for example, devices 210, 410,610 or 810, may include the wake-up feature described herein, where thedepression of the dose button to its distal position during initial dosedelivery can activate the controller. For example, upon the sensing ofthe initial one of surface features, the controller of electronicsassembly is configured to allow wake-up or activate the electronicsassembly to a full power state. Triggering of wake-up feature isconfigured to allow power transmission from the power source (shown asbattery) for powering up the electronic components for dose sensing inorder to minimize inadvertent power loss or usage when a dose dispensingevent is not occurring. In other embodiments, a separate wake-up switchmay be provided and arranged within the dose button housing of any oneof the devices described herein and triggered when the dose button is inits distal position. In this instance, the wake-up switch may belocated, for example, along the upper end of the flange.

In some embodiments, a single sensing system may be employed for bothdose detection sensing and wake-up activation. For example, the devicesdescribed herein, such as, for example, devices 210, 410, 610 or 810,may having a controller configured to, upon the sensing of the initialfirst surface feature, allow wake-up or activation of the electronicsassembly to a full power state. Subsequently, the controller isconfigured to, upon the sensing of the first surface feature (or secondin order) after the initial first surface feature, count the totalnumber of surface features until rotation of the dose setting member isstopped upon completion of the dose dispensing phase. One of theadvantages of a single system with this abundant functionality is thatmay reduce the number of electronic components in the device as well asthe manufacturing complexity with additional sensors.

The shown device is a reusable pen-shaped medication injection device,generally designated, which is manually handled by a user to selectivelyset a dose and then to inject that set dose. Injection devices of thistype are well known, and the description of device is merelyillustrative as the sensing system can be adapted for use in variouslyconfigured medication delivery devices, including differentlyconstructed pen-shaped medication injection devices, differently shapedinjection devices, and infusion pump devices. The medication may be anyof a type that may be delivered by such a medication delivery device.Device is intended to be illustrative and not limiting as the sensingsystem described further below may be used in other differentlyconfigured devices.

To clarify the use of and to hereby provide notice to the public, thephrases “at least one of <A>, <B>, . . . and <N>” or “at least one of<A>, <B>, . . . <N>, or combinations thereof” or “<A>, <B>, . . . and/or<N>” are defined by the Applicant in the broadest sense, superseding anyother implied definitions hereinbefore or hereinafter unless expresslyasserted by the Applicant to the contrary, to mean one or more elementsselected from the group comprising A, B, . . . and N. In other words,the phrases mean any combination of one or more of the elements A, B, .. . or N including any one element alone or the one element incombination with one or more of the other elements which may alsoinclude, in combination, additional elements not listed.

While various embodiments have been described, it will be apparent tothose of ordinary skill in the art that many more embodiments andimplementations are possible. Accordingly, the embodiments describedherein are examples, not the only possible embodiments andimplementations. Furthermore, the advantages described above are notnecessarily the only advantages, and it is not necessarily expected thatall of the described advantages will be achieved with every embodiment.

Various aspects are described in this disclosure, which include, but arenot limited to, the following aspects:

1. A medication delivery device including: a device body; a dose settingmember attached to the device body and rotatable relative to the devicebody about an axis of rotation during dose delivery; a sensed elementattached to and rotationally fixed with the dose setting member, thesensed element including axially extending surface featuresradially-spaced from one another about the axis of rotation of the dosesetting member; an actuator attached to the device body, wherein thesensed element is rotatable relative to the actuator during dosedelivery in relation to the amount of dose delivered; a rotationalsensor attached to the actuator, the rotational sensor including amovable element positionable to slidably contact the axially extendingsurface features during rotation of the sensed element relative to theactuator during dose delivery, the rotational sensor configured togenerate a signal in response to a triggering of the movable elementover the axially extending surface features during the rotation of thedose setting member; and a controller operatively coupled to therotational sensor, wherein, in response to receiving the generatedsignal from the rotational sensor, the controller is configured todetermine a number of the axially extending surface features passing themovable element of the rotational sensor during dose delivery.

2. The medication delivery device of aspect 1, wherein the axiallyextending surface features include alternating projections and recesses,the movable element riding against the projections and recesses duringrotation of the sensed element relative to the actuator during dosedelivery.

3. The medication delivery device of aspect 2, wherein the projectionsextend proximally from the dose setting member.

4. The medication delivery device of any one of aspects 1-3, wherein thedose setting member is a flange or a dose dial member.

5. The medication delivery device of any one of aspects 1-4, wherein therotational sensor includes a switch, wherein the movable elementalternately engaging or disengaging the axially extending surfacefeatures is operable to trigger the switch and generate the signal.

6. The medication delivery device of any one of aspects 1-5, wherein theactuator has a first position in which the movable element of therotational sensor is disengaged from the axially extending surfacefeatures.

7. The medication delivery device of aspect 6, wherein the actuator hasa second position in which the movable element of the rotational sensoris contactable with the axially extending surface features.

8. The medication delivery device of aspect 7, wherein, when theactuator is in the second position, the controller is configured, uponreceiving a signal indicative of contact with an initial first one ofthe axially extending surface features, to activate the controller to afull power state, and the controller is configured, upon receiving asignal indicative of contact with a subsequent one of the axiallyextending surface features after the initial first one, to determine anumber of the axially extending surface features passing the movableelement of the rotational sensor during dose delivery.

9. The medication delivery device of any one of aspects 1-8, wherein themovable element includes at least one contact by which upon engagementwith the axially extending surface features is operable to generate thesignal.

10. The medication delivery device of aspect 9, wherein the at least onecontact include a pair of contacts, wherein upon engagement of one ofthe pair of contacts with the axially extending surface is configured tomove into contact with the other of the pair of contacts to generate thesignal.

11. The medication delivery device of any one of aspects 1-8, whereinmovement of the movable element relative to the axially extendingsurface features is configured to generate rotation vibrations, whereinthe rotational sensor is configured to generate the signal in responseto detection of the rotation vibrations.

12. The medication delivery device of aspect 11, wherein the rotationalsensor includes a rotation accelerometer operable to detect the rotationvibrations.

13. The medication delivery device of aspect 12, wherein the rotationalsensor further includes a ground accelerometer operable to detect groundvibrations, the controller is configured to compare the rotation andground vibrations and configured to determine vibrations indicative ofrotation of the sensed element relative to the actuator during dosedelivery from the comparison.

14. The medication delivery device of any one of aspects 1-8, whereinmovement of the movable element relative to the axially extendingsurface features is configured to generate rotation sounds, wherein therotational sensor is configured to generate the signals in response todetection of the rotation sounds.

15. The medication delivery device of any one of aspects 1-14, furtherincluding a module removably attached to the actuator, the moduleincluding the movable element for engagement with the sensed element ofthe dose setting member of the device body that is outside the module.

16. The medication delivery device of any one of aspects 1-8, whereinthe rotational sensor includes a piezoelectric sensor.

17. A medication delivery device including: a device body; a dosesetting member attached to the device body and rotatable relative to thedevice body about an axis of rotation during dose delivery, wherein thedose setting member includes a sensed element, the sensed elementincluding surface features radially-spaced from one another about theaxis of rotation of the dose setting member; a dose button attached tothe device body, wherein the sensed element is rotatable relative to thedose button during dose delivery in relation to the amount of dosedelivered, wherein the dose button houses a rotational sensor, therotational sensor including a movable element positionable to slidablycontact the surface features during rotation of the sensed elementrelative to the dose button during dose delivery, the rotational sensorconfigured to generate a signal in response to the movement of themovable element over the surface features during the rotation of thedose setting member, wherein the dose button has a first position inwhich the movable element of the rotational sensor is disengaged fromthe surface features, and a second position in which the movable elementof the rotational sensor is contactable with the surface features; and acontroller operatively coupled to the rotational sensor and housed bythe dose button, wherein, in response to receiving the generated signalfrom the rotational sensor, the controller is configured to determine anumber of the surface features passing the movable element of therotational sensor during dose delivery, wherein, when the dose button isin the second position, the controller is configured, upon receiving asignal indicative of contact with an initial first one of the surfacefeatures, to activate the controller to a full power state, and thecontroller is configured, upon receiving a signal indicative of contactwith a subsequent one of the surface features after the initial firstone, to determine a number of the axially extending surface featurespassing the movable element of the rotational sensor during dosedelivery.

18. The medication delivery device of aspect 17, wherein the rotationalsensor includes a switch.

19. The medication delivery device of aspect 17, wherein the rotationalsensor includes at least one contact.

20. The medication delivery device of aspect 17, wherein the rotationalsensor includes a piezoelectric sensor.

21. The medication delivery device of aspect 17, wherein the surfacefeatures axially extend from the dose setting member.

22. The medication delivery device of any one of the preceding aspects,further comprising a bias member axially disposed between the dosebutton and the dose setting member, wherein the rotational sensor andthe controller are disposed within a cavity of the dose button, and thesurface features are disposed within the cavity radially outside thebias member.

23. The medication delivery device of any one of the preceding aspects,wherein the device body includes a reservoir having a medication.

We claim:
 1. A medicament delivery device comprising: a reservoir formedicament; a dispensing mechanism operable to dispense medicament fromthe reservoir, the dispensing mechanism comprising a componentconfigured to rotate during the dispensing of medicament and having aplurality of formations extending therefrom; and a dosage measurementsystem comprising at least one mechanically actuated sensor configuredsuch that, in use, rotation of the component causes successiveformations to engage the sensor such that the sensor detects rotation ofthe component and a processor configured to determine data indicative ofa dosage dispensed from the reservoir based on the detected rotation ofthe component, wherein the sensor comprises a switch that comprises apair of contacts, wherein when the switch is engaged by one of theformations during rotation of the component, the pair of contacts isconfigured to generate an electrical signal by (i) moving into contactwith one another or (ii) separating from a contacting relationship withone another.
 2. The medicament delivery device according to claim 1,wherein the plurality of formations comprise a plurality of teeth. 3.The medicament delivery device according to claim 1, wherein thecomponent is a flange and the formations are formed on a proximal end ofthe flange.
 4. The medicament delivery device according to claim 3,wherein the flange is attached to a proximal end of a dose dial member.5. The medicament delivery device according to claim 1, comprising adose button and a housing, wherein the dose button is configured to berotated relative to the housing to set a dose of medicament to bedelivered by the dispensing mechanism and wherein the sensor is mountedto the dose button.
 6. The medicament delivery device according to claim1, further comprising a medicament stored in the reservoir.
 7. A dosagemeasurement system for a medicament delivery device, wherein themedicament delivery device comprises: a housing containing a reservoirfor medicament; a dispensing mechanism operable to dispense medicamentfrom the reservoir and comprising a component configured to rotateduring dispensing of medicament, the component comprising a plurality offormations, and an actuator configured to be movable relative to thehousing upon actuation to operate the dispensing mechanism to dispensemedicament from the reservoir, the dosage measurement system comprising:a sensor moveable from an idle position in which the sensor isdisengaged from the plurality of formations during rotation of thecomponent to a detecting position wherein rotation of the componentcauses successive formations to be detected by the sensor such that thesensor detects rotation of the component; and a processor configured todetermine a dosage dispensed from the medicament reservoir based on thedetected rotation of the component.
 8. The dosage measurement systemaccording to claim 7, wherein the sensor is axially displaced from theplurality of formations when the sensor is in the idle position.
 9. Thedosage measurement system according to claim 7, wherein the medicamentdelivery device further comprises medicament stored in the reservoir.